US4159387A
Expired / Lapsed
US
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Squaric acid esters
Assignee: Novartis Corp
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Filing: 1977-11-23
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Granted: 1979-06-26
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Expires: 1997-11-23
Abstract
Abstract There are described new squaric acid esters, particularly mono-ortho esters, di-ortho esters, ortho ester anhydrides and ortho ester halides of squaric acid; a new process for producing these squaric acid esters; and a process for converting the squaric acid esters into squaric acid. It is possible by the new process to produce, with the use of readily obtainable starting products, the new squaric acid esters according to the invention in an economical manner and with good to very good yields; and the squaric acid esters can be converted under mild reaction conditions into squaric acid.
Inventors
- 👤 Daniel Bellus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:18
CPC Classifications
C; C07; C07C; C07C49/00; C07C49/587; C07C49/753; C07C45/00; C07C45/45; C07C45/51; C07C45/54; C07C45/61; C07C45/67; C07C45/673; C07C69/00; C07C69/66; C07C69/67; C07C69/708
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
74 words
A compound of the formula I ##STR18## wherein X 1 and X 2 together represent the grouping ═O, Z 1 represents a group --OR 1 , and Z 2 represents a chlorine, bromine or fluorine atom or a group --OR 2 ; with R 1 representing a primary or secondary alkyl group having 1-4 carbon atoms, and R 2 an alkyl group having 1-4 carbon atoms or an alkanoyl group having 2-4 carbon atoms.
Claim 2
Dependent Claim
74 words
A compound of the formula I ##STR18## wherein X 1 and X 2 together represent the grouping ═O, Z 1 represents a group --OR 1 , and Z 2 represents a chlorine, bromine or fluorine atom or a group --OR 2 ; with R 1 representing a primary or secondary alkyl group having 1-4 carbon atoms, and R 2 an alkyl group having 1-4 carbon atoms or an alkanoyl group having 2-4 carbon atoms.
Claim 3
Dependent Claim
49 words
A compound of the formula I according to claim 1, wherein X 1 and X 2 together represent the grouping ═O, Z 1 represents the methoxy or ethoxy group, Z 2 represents a chlorine atom, the methoxy or ethoxy group, and R 1 represents the methyl or ethyl group.
Claim 4
Dependent Claim
10 words
A compound according to claim 1, of the formula ##STR19##
Claim 5
Dependent Claim
10 words
A compound according to claim 1, of the formula ##STR20##
Claim 6
Dependent Claim
10 words
A compound according to claim 1, of the formula ##STR21##
Claim 7
Dependent Claim
10 words
A compound according to claim 1, of the formula ##STR22##
Claim 8
Dependent Claim
92 words
A compound of the formula I ##STR23## wherein x 1 and x 2 represent a group --OR 1 , Z 1 represents a chlorine, bromine or fluorine atom or a group --OR 2 , Z 2 represents a group --OCOCH 2 --Cl, --OCOCH 2 --Br, --OCOCH 2 --F or --OCOCH 2 DR 2 , R 1 represents a primary or secondary alkyl group of 1 to 4 carbon atoms, and R 2 is an alkyl group of 1 to 4 carbon atoms or an alkanoyl group of 2 to 4 carbon atoms.
Claim 9
Dependent Claim
92 words
A compound of the formula I ##STR23## wherein x 1 and x 2 represent a group --OR 1 , Z 1 represents a chlorine, bromine or fluorine atom or a group --OR 2 , Z 2 represents a group --OCOCH 2 --Cl, --OCOCH 2 --Br, --OCOCH 2 --F or --OCOCH 2 DR 2 , R 1 represents a primary or secondary alkyl group of 1 to 4 carbon atoms, and R 2 is an alkyl group of 1 to 4 carbon atoms or an alkanoyl group of 2 to 4 carbon atoms.
Claim 10
Dependent Claim
71 words
A compound of the formula I according to claim 7, wherein X 1 and X 2 are the same and each represent a methoxy or ethoxy group, Z 1 represents a chlorine atom, a methoxy, ethoxy or acetyloxy group, Z 2 represents a group --OCOCH 2 Cl, --OCOCH 2 OCH 3 , --OCOCH 2 OC 2 H 5 or --OCOCH 2 OCOCH 3 , and R 1 represents methyl or ethyl.
Claim 11
Dependent Claim
10 words
A compound according to claim 7, of the formula ##STR24##
Claim 12
Dependent Claim
10 words
A compound according to claim 7, of the formula ##STR25##
Claim 13
Dependent Claim
10 words
A compound according to claim 7, of the formula ##STR26##
Claim 14
Dependent Claim
10 words
A compound according to claim 7, of the formula ##STR27##
Claim 15
Dependent Claim
10 words
A compound according to claim 7, of the formula ##STR28##
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-06-25 | 1982-12-25 | 1983-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-06-25 | 1986-12-25 | 1987-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-06-25 | 1990-12-25 | 1991-06-26 | $7700.00 | Window Closed / Lapsed |